Along with continuous development of a communication network technology, a communication network may be utilized to transmit a current to supply power to electric equipment in the network at the same time when the communication network is utilized to transmit an information flow. For example, Ethernet is utilized to supply power to electronic equipment such as an Internet telephone, a wireless access point, a monitoring camera and terminal switching equipment in the network. For another example, a telephone network is utilized to supply power to electronic equipment such as a telephone set, a nightlight and environment monitoring equipment in the telephone network. Utilizing a communication network to supply power to equipment solves the problem of difficulties in electricity taking, improves flexibility in use of the equipment and reduces mounting complexity and using cost of the equipment. Power on or power off of equipment may also be remotely controlled via the communication network.
Along with wide application of a communication-network-based power supply technology, an electro-load in a communication network has an electricity demand of higher power. In order to implement higher-power communication-network-based power supply, two or more than two pieces of Power Sourcing Equipment (PSE) may usually be adopted to supply power to the same electro-load. When an interface controller receives power supplied by the PSE, currents in two or more than two power supply lines are made to be the same through a current equalization module at first, and then are output to the electro-load through a Direct Current/Direct Current (DC/DC) voltage converter. Different power supply distances of the PSE and different loss in the power supply lines cause great voltage differences between ports of the interface controller. In an existing solution, non-DC/DC conversion is performed on voltage of each of input ports to compensate the voltage differences between input ports to implement current equalization. However, a voltage compensation range brought by such a method is limited, so that a current equalization effect is poor. Moreover, the voltage differences between the input ports are greater, the loss is higher, and thus the efficiency is lower.